Method and apparatus for modifying sucker rod

ABSTRACT

Method and apparatus for removing a scraper apparatus from the outer peripheral surface of a sucker rod, comprising; aligning the individual bands holding the scraper apparatus to the wall surface of the rod with a set of diametrically opposed cutting means; engaging opposed portions of the band with the opposed cutting means and exerting a sufficient force to cause the bands to be severed along two opposed longitudinally extending portions thereof, so as to release the scraper apparatus from the sucker rod. Stop means on the cutting means prevents injury or damage to the rod.

United States Patent [1 1 Clark, Jr.

METHOD AND APPARATUS FOR MODIFYING SUCKER ROD [56] References Cited UNITED STATES PATENTS 311,738 2/1885 Fladd 83/612 1,443,880 1/1923 l(naack.... 30/178 1,091,726 3/1914 Berry 83/452 3,418,874 12/1968 LBBS..... 83/600 I 1,155,375 1 9 19 2 9 1 30/180 Nov. 27, 1973 6/1926 Campen 30/180 5/1907 Weiss 30/177 Primary Examiner-Charles W. Lanham Assistant Examiner.lames R. Duzan Attorney-Marcus L. Bates [57 ABSTRACT Method and apparatus for removing a scraper apparatus from the outer peripheral surface of a sucker rod, comprising; aligning the individual bands holding the scraper apparatus to the wall surface of the rod with a set of diametrically opposed cutting means; engaging opposed portions of the band with the opposed cutting means and exerting a sufticient force to cause the bands to be severed along two opposed longitudinally extending portions thereof, so as to release the scraper apparatus from the sucker rod. Stop means on the cutting means prevents injury or damage to the rod.

, 3 9 99 5 Dmwiasfi BACKGROUND OF THE INVENTION The bottom hole pressure of most oil wells is of an insufficient value to cause liquids therein to freely flow to the surface of the earth, and accordingly, a downhole reciprocating type production pump is employed in order to force the liquid to flow from the lower extremity of the borehole to the surface of the ground. The reciprocating downhole pump generally is actuated by joints of sucker rod made up into a string extending several thousand feet from the surface of the earth down to the production pump so as to enable a pump jack located at the surface of the ground to reciprocate the rod which in turn actuates the downhole production pump.

Often, paraffinic hydrocarbons precipitate out and crystallize on the walls within the production tubing, and for this reason it is common to employ various types of scrapers on the exterior surface of the sucker rod. The reciprocal motion of the sucker rod causes the scrapers to dislodge the paraffin from the inside wall surface of the tubing, whereupon it flows out through the production tubing. Those skilled in the art are familiar with scraper apparatus such as may be identified as the Huber Petco, the Krawl, or the Sunshine (all trade names), for example. Throughout this disclosure, the term scraper is intended to relate to these and other similar types of scraper design which lend themselves to use in conjunction with the present invention.

Reconditioning sucker rod by shot peening and subsequent electronic examination entails the necessity of removing the scraper apparatus from the rod, for otherwise, used rod cannot be reconditioned properly for return to service. It is for this reason that the presence of the scraper on the old rod usually reduces to junk an otherwise valuable rod.

It is therefore desirable to have a means by which the scraper on a sucker rod can be removed in an efficient, reliable, and economical manner. Furthermore, such an expedient should be able to remove the scraper rapidly without damaging the structural integrity of the rod.

SUMMARY OF THE INVENTION This invention relates to method and apparatus for removing scraper apparatus from the outer wall surface of a sucker rod by aligning the bands holding the scraper to the rod with diametrically opposed cutting means, forcing the cutting means into engagement with the bands so as to enable the cutting means to commence cutting into the bands, and increasing the force exerted by the cutting means until the bands are severed to thereby enable the entire scraper device to be released from the rod.

The apparatus includes legs which are journaled together in scissor-like relationship, with one adjacent depending end of the legs being forced together and apart; and with the remaining adjacent depending ends of the legs having the cutting means attached thereto for cutting the scraper bands from the rod.

When the cutting means are forced towards one another, with the rod disposed therebetween, a stop means associated with the cutting means enables the bands to be severed in a manner which precludes damage to the rod. 2

A primary object of this invention is to provide a method for removing scraper apparatus from the outer wall surface of a sucker rod.

Another object of the present invention is the provision of apparatus for removing a scraper from the exterior surface of a sucker rod by cutting the bands holding the scraper to the rod in diametrically opposed locations.

A further object of the present invention is the provision of apparatus for removing a scraper from the outer wall surface of a sucker rod which includes means for obviating damage to the rod.

A still further object of this invention is to provide method and apparatus by which the bands attaching a scraper apparatus to sucker rod can be removed from the rod without adversely affecting the structural integrity of the rod.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.

The above objects are attained in accordance with the present invention by the provision of a method for use with apparatus fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a sucker rod having an ordinary scraper of the prior art attached thereto;

FIG. 2 is a crosssectional view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged broken cross-sectional view showing further details of FIG. 2;

FIG. 4 is a cross-sectional view showing an important feature of the present invention;

FIG. 5 is a cross-sectional view showing another important feature of the present invention;

FIG. 6 is an enlarged fragmentary cross-sectional view of a part of the apparatus disclosed in FIG. 5;

FIG. 7 is a fragmentary side elevational view of apparatus used in conjunction with the present invention;

FIG. 8 is a partial side elevational view of apparatus used in conjunction with FIG. 7',

FIG. 9 is an end view of the apparatus disclosed in FIG. 7;

FIG. 10 is an enlarged end view of part of the apparatus disclosed in FIG. 7; and

FIG. 11 is an enlarged fragmentary side elevational view of the jaws disclosed in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION FIGS. l3 disclose a prior art sucker rod 9 having a scraper apparatus 11 disposed thereon, with bands 13 suitably securing the scraper blades 12 to the rod. The scraper blades are comprised of a limited length of flat metal that is formed into a spiral and joined to the rod by the spaced apart bands. The spiraled blade has terminal end portions 14 and 15. The bands are limited in width and extend 360 circumferentially about a portion of the exterior surface of the rod. The scraper blades are usually welded to the bands, with the bands being permanently attached to the rod by a close tolerance fit.

As best seen in FIG. 4, diametrically spaced apart metal cutting means 16 and 17 are forced together so that a cutting edge at 18 engages a band of the rod. It

will be noted that the center line 19 of the rod can be off-set from the center line 20 of the spaced apart cutting means, if desired, this expedient intended to represent a second embodiment of the invention. In the first embodiment the cutting means is considered to be aligned along the center line 20.

In FIG. 5 the band has been severed by the cutting means into individual pieces 13 and 13" leaving the rod 9 free of the scraper apparatus.

In the details of FIG. 6, band 13' represents one that has been cut by a die, and is seen to have an outer peripheral surface 45 which has received a preliminary cut 46 which slightly changes direction at 47, with portion 48 of the metallic band apparently being broken or fractured.

As seen in FIGS. 7-10, apparatus 19 is conveniently mounted upon structure 20' with a fixed arm 21 being attached to and bottom supported thereby. Movable arm 22 is journaled to arm 21 by means of a journal 23. Arms 21 and 22 are therefore journaled together in a scissor-like relationship.

Hydraulically actuated cylinder 24 is journaled at 25 to one free end portion of the fixed arm while the piston thereof is journaled to one free end portion of the movable arm by means of the journal 26.

The cutting end 27 of the apparatus is provided with the before illustrated chisel-like elements 16 and 17, also referred to as a die, with the cutting means being spaced apart from the journal means 23 a much smaller amount as compared to the distance measured between the cylinder 24 and the journal means 23. The dies are seen to be affixed to the remaining free end portions of the legs. I a

An elongated member 28 has a cutout formed in the pivoted or free depending end 28' thereof so that the cutout can receive the rod in close fitting relationship therewithin. Handle 29 facilitates pivoting the member into engagement with a rod, and is spring loaded so as to maintain the member normally pivoted into the retracted position in the illustrated manner of FIG. 7. Journal 31 movably affixes the member to the reinforcing pad 31. The reinforcing pad is welded to either side of the fixed arm and provides a means for supporting the journal 23.

A source of hydraulic fluid pressure (not shown) is connected to the cylinder by an in-flow, outflow connection 32, all in a conventional manner, according to prior art techniques.

Diametrically opposed support members 33, 34 each depend from the fixed arm so as to provide a means for mounting a member 28 on either side of the arm.

Spaced apart from the apparatus 19 is a rotatable disk 35 which is journaled to horizontal member 35. Stanchion 36 is affixed to mount 20 while the angular disposed member 37 abuts stop means 38. Member 35 can be moved in an arcuate-like manner about the journal formed at 36 so as to enable the apparatus to be retracted into a position which is clear of the rod being worked on.

A v-shaped support channel 39 receives rods therein with the rods extending from 39 into the similarly constructed v-shaped channel 40 so that the rods are disposed along the dot-dashed line seen at 41.

Control panel 42 controls portions of the operation including a motor driven pump which provides the source of hydraulic fluid pressure to the cylinder 24. A foot control means 44 enables the operator to use both hands for manipulating the rod while the foot control is utilized for controlling the action of the piston of the hydraulic cylinder assembly.

The metal cutting means is comprised of removable dies 17 and 18 having opposed faces such as seen in FIG. 10. The face includes a land 16' which reduces in thickness to form a cutting edge 18 of limited length. The length of the cutting edge l is determined by the spaced apart lands and must be greater than the width of the band 13 so that when the cutting edges of the diametrically opposed faces of the dies are brought into engagement with the band, the band is severed into two spaced apart pieces as seen in FIG. 5, while the lands act as stop members as they are brought to bear against the rod surface.

In operation, joints of sucker rod, having any configuration of banded scraper apparatus 11 thereon, are sequentially placed into the channel 39 whereupon the rod is then moved along the dot-dashed line 41 so that each band on the rod can be brought under the dies in a sequential manner. The guide means 28 and 35 guides and holds the rod as it progresses from member 39 into or along member 40, following a path of travel 41, with the cleaned or stripped rod being received at 40, and the rod portion at 39 is yet to be cleaned.

The rod bears against the spaced apart plates 35, and a band is placed under length l of the blade 18 of the cutting means. The handle 29 pivots member 28 into engagement with the rod, so as to prevent movement thereof until the diametrically opposed blades engage and form the initial cut 46 in the band. The blades are moved towards one another by foot control 44 which causes hydraulic fluid to enter the cylinder at 32, forcing the journals 25, 26 apart, and the opposed faces of the cutting means together, as the blades continue to cut along line 47, until the bands are severed in the manner of FIG. 5.

The bands will usually part prior to the blade progressing through part 48 (FIG. 6), that is, the band usually springs apart without having the blade pass entirely therethrough. The die faces continue into contact with the rod, and it is for this reason that the novel opposed lands must stop or hold the cutting edge clear of the rod surface, or otherwise the rod will be cut by the blade.

Where the band fails to spring apart in the manner of FIGS. 5 and 6, it is necessary to adjust the blade alignment 20 so as to slightly off-set the cutting edges with centerline 19 of the rod. This expedient forces the bands to part into two pieces in the manner of FIG. 6, with the two pieces springing apart, and falling from the rod so that subsequent work of removal of the bands and scrapers from the rod is not required.

The cutting means can be easily replaced on the jaws by merely removing the illustrated fastener means. The guide means 28 and 35 can be pivoted out of the way when desired. The control panel 42 actuates the various motors, controllers, and accessories associated with the instant apparatus.

I claim:

1. Apparatus for removing scrapers from sucker rod, wherein the scraper is attached to the rod by a band circumferentially disposed about a limited length of the rod, comprising:

spaced opposed dies, each die having a face which includes a cutting edge and a land formed thereon, with the cutting edge disposed parallel to the land so that the land and cutting edge lie in substantially the same horizontal plane;

means for moving one die towards the other die so that each face of the dies may be brought to bear against opposed surface areas of the band on the rod;

each said die includes two said lands which are spaced apart from one another by said cutting edge, with the distance between the lands being greater than the width of a band, so that the cutting edge moves through the band until the lands contact the surface of the rod, thereby preventing the cutting edge from engaging and damaging the rod;

said means for moving one die towards another die includes a pair of legs journaled together at an intermediate portion thereof;

a die receiving jaw located at adjacent free end portions of the legs; means by which said die is removably received within said jaw;

means for moving the other adjacent free end portions of the legs towards and away from one another so that movement of said other adjacent free end portions away from one another causes the jaws to be moved towards one another; and, guide means for maintaining a sucker rod longitudinally aligned with said cutting edge so that the band on the rod can be engaged by the cutting edge.

2. The apparatus of claimtl wherein the cutting edges are brought to bear against the band at positions which are less than apart.

3. In a sucker rod having a scraper device attached thereto by spaced bands, the method of removing the scraper device therefrom comprising the steps of:

aligning the bands with diametrically opposed cutting means;

arranging a land on each cutting means with the land lying parallel to a cutting edge so that the land engages the outer peripheral surface of the rod at a position spaced from the band while the cutting edge engages and cuts the band but is prevented from engaging the rod;

forcing the cutting means into engagement with opposed surface areas of the bands which are less than 180 apart; increasing the force against the cutting means until the bands are severed into two semicircular pieces, one piece being more than 180 and the other piece being less than 180 in circumference. 

1. Apparatus for removing scrapers from sucker rod, wherein the scraper is attached to the rod by a band circumferentially disposed about a limited length of the rod, comprising: spaced opposed dies, each die having a face which includes a cutting edge and a land formed thereon, with the cutting edge disposed parallel to the land so that the land and cutting edge lie in substantially the same horizontal plane; means for moving one die towards the other die so that each face of the dies may be brought to bear against opposed surface areas of the band on the rod; each said die includes two said lands which are spaced apart from one another by said cutting edge, with the distance between the lands being greater than the width of a band, so that the cutting edge moves through the band until the lands contact the surface of the rod, thereby preventing the cutting edge from engaging and damaging the rod; said means for moving one die towards another die includes a pair of legs journaled together at an intermediate portion thereof; a die receiving jaw located at adjacent free end portions of the legs; means by which said die is removably received within said jaw; means for moving the other adjacent free end portions of the legs towards and away from one another so that movement of said other adjacent free end portions away from one another causes the jaws to be moved towards one another; and, guide means for maintaining a sucker rod longitudinally aligned with said cutting edge so that the band on the rod can be engaged by the cutting edge.
 2. The apparatus of claim 1 wherein the cutting edges are brought to bear against the band at positions which are less than 180* apart.
 3. In a sucker rod having a scraper device attached thereto by spaced bands, the method of removing the scraper device therefrom comprising the steps of: aligninG the bands with diametrically opposed cutting means; arranging a land on each cutting means with the land lying parallel to a cutting edge so that the land engages the outer peripheral surface of the rod at a position spaced from the band while the cutting edge engages and cuts the band but is prevented from engaging the rod; forcing the cutting means into engagement with opposed surface areas of the bands which are less than 180* apart; increasing the force against the cutting means until the bands are severed into two semicircular pieces, one piece being more than 180* and the other piece being less than 180* in circumference. 